Unfortunately, moms have gotten the idea from the bottle-feeding world that
quantity is the measure of the quality of the feeding.  But as you point out,
the make-up of breast milk changes as the baby's need changes.  And
therefore, quantity of EBM at a feeding may not be the factor to look at.

What I suggest to moms is that they bottle/freeze their milk in two-ounce 
amounts in the early days; then in four-ounce portions.  This way they
can feed the baby "on demand" and to the baby's needs at the particular
feeding, without having to throw away (too much) breastmilk because they
exposed too much to baby's saliva and bacteria.

Then, IMO, when feeding bottle feeding, moms need to learn the same baby watching/ feeding cues as when breast feeding.  How do you know that the baby's done?  He stops eating, he's ready to play,  he falls asleep. . .
How do you know the baby's hungry still?  After a burp, he still wants more, he is not diverted by other comfort measures. . .

 Just as breastfeeding babies vary in their eating modes, so do they
do at bottle -- take breaks midfeed to play, snooze, temporarily pay
attention to something else.  So you don't stop offering the first time
they take a break, but neither do you force feed.  I would like to see
bottle fed babies accorded at least the same attention as those fed
at the breast.  If they must be deprived of the breast itself, or even breast
milk, they should at least be allowed the opportunities for the other
connections and developmental growth that feeding at the breast brings. 

I know many moms, dads and other caregivers want a quantity amount.
Maybe we can develop "least minimums" and "most maximums," but I 
truly believe that even when bottlefeeding, baby has to be the guide.

So in a way, there are two questions.  Mom wants to know how much to
pump out for a feeding?  As much as she can.  She wants to know how
much the baby should eat?  In most cases, as much as he will.

Sorry if I seem to be on a bandwagon here, between this and a previous
post, but in a way I am.  I truly believe in "best-feeding."  And I think baby's who must take a bottle, or
worse yet, ABM, are already deprived, without being treated as second-
class citizens as well. (Even if the baby has to take second-best, or
third-best,  shouldn't it should be the best un-breast it can be?)

Chanita, in San Francisco